CVE-2026-21861

HIGHNVD 7.27.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.2 under NVD CVSS v3. EPSS exploit probability: 2.3%, top 18% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 7.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

baserCMS is a website development framework. Prior to version 5.2.3, baserCMS contains an OS command injection vulnerability in the core update functionality. An authenticated administrator can execute arbitrary OS commands on the server due to improper handling of user-controlled input that is directly passed to exec() without sufficient validation or escaping. This issue has been patched in version 5.2.3.

CVSS v3
7.2
EG Score
7.2(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity72% × 45%
Exploitation2% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
82%
KEV
Not listed

Published

March 31, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Aug 3, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available

OS Command Injection Leading to Remote Code Execution (RCE) · Advisory · baserproject/basercms · GitHub

https://github.com/baserproject/basercms/security/advisories/GHSA-qxmc-6f24-g86g
github_release Patch Available

baserCMS 5.2.3 リリース

Patch available: baserproject/basercms 5.2.3

https://github.com/baserproject/basercms/releases/tag/5.2.3

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
baserproject/basercms2.0.0-rc1 ... 5.2.2 (145 versions)5.2.3—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-12 15:01 UTCEPSS rescore
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-10 09:34 UTCEPSS rescore
  5. 2026-09-08 22:00 UTCEPSS rescore
  6. 2026-09-07 16:01 UTCEPSS rescore
  7. 2026-09-06 13:47 UTCEPSS rescore
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-04 05:06 UTCEPSS rescore
  10. 2026-09-02 14:11 UTCEPSS rescore
  11. 2026-09-02 12:44 UTCOSV refresh
  12. 2026-09-01 13:53 UTCEPSS rescore
  13. 2026-09-01 04:39 UTCEPSS rescore
  14. 2026-08-30 19:17 UTCEPSS rescore
  15. 2026-08-30 01:22 UTCEPSS rescore
  16. 2026-08-28 21:41 UTCEPSS rescore
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-26 14:46 UTCEPSS rescore
  19. 2026-08-25 13:48 UTCEPSS rescore
  20. 2026-08-23 00:19 UTCEPSS rescore
  21. 2026-08-21 23:49 UTCEPSS rescore
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-19 17:03 UTCEPSS rescore
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-17 13:47 UTCEPSS rescore
Show 30 more
  1. 2026-08-16 14:56 UTCEPSS rescore
  2. 2026-08-16 09:43 UTCEG score recompute
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-14 06:06 UTCEG score recompute
  6. 2026-08-13 22:00 UTCEPSS rescore
  7. 2026-08-12 20:27 UTCEG score recompute
  8. 2026-08-12 13:50 UTCEPSS rescore
  9. 2026-08-11 20:39 UTCEG score recompute
  10. 2026-08-11 13:42 UTCEPSS rescore
  11. 2026-08-11 03:39 UTCEG score recompute
  12. 2026-08-11 00:00 UTCEPSS rescore
  13. 2026-08-09 17:56 UTCEG score recompute
  14. 2026-08-09 13:46 UTCEPSS rescore
  15. 2026-08-09 05:41 UTCEG score recompute
  16. 2026-08-08 16:37 UTCEPSS rescore
  17. 2026-08-08 04:02 UTCEG score recompute
  18. 2026-08-06 18:14 UTCEG score recompute
  19. 2026-08-06 13:46 UTCEPSS rescore
  20. 2026-08-06 00:39 UTCEG score recompute
  21. 2026-08-05 19:17 UTCEPSS rescore
  22. 2026-08-04 15:10 UTCEPSS rescore
  23. 2026-08-04 10:38 UTCEPSS rescore
  24. 2026-08-03 22:58 UTCEG score recompute
  25. 2026-08-03 10:35 UTCEPSS rescore
  26. 2026-08-02 15:01 UTCEG score recompute
  27. 2026-08-02 02:26 UTCEPSS rescore
  28. 2026-08-01 04:15 UTCEPSS rescore
  29. 2026-07-30 01:30 UTCEPSS rescore
  30. 2026-07-27 14:17 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21861?
CVE-2026-21861 is a high vulnerability published on March 31, 2026. baserCMS is a website development framework. Prior to version 5.2.3, baserCMS contains an OS command injection vulnerability in the core update functionality. An authenticated administrator can execute arbitrary OS commands on the server due to improper handling of user-controlled input that is…
When was CVE-2026-21861 disclosed?
CVE-2026-21861 was first published in the National Vulnerability Database on March 31, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21861 actively exploited?
CVE-2026-21861 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 17.8% of all scored CVEs.
What is the CVSS score of CVE-2026-21861?
CVE-2026-21861 has a CVSS v3 base score of 7.2 (NVD).
How do I remediate CVE-2026-21861?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21861, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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